Parallel Arguments or Analogies If you are given

Parallel Arguments, or Analogies If you are given an argument that you are not familiar with, it may be easier to work out what is happening, if you can compare it to a similar argument of a similar structure. A: “I mean what I say, because I say what I mean”. B: “That is like saying that you eat what you see, because you see what you eat…” What is the logical structure of the parallel arguments above? x: y because y: x Does the analogy illuminate the argument as stronger or weaker? Feeding our addiction to air travel by building new runways must be wrong in the same way that it has been proven that giving alcohol to an alcoholic causes health problems. A is to B, as C is to D. What parts of the argument does this logical structure represent? A: giving roads to car addicts is B: dangerous C: giving alcohol to alcoholics is D: dangerous Does the analogy work? Is it illuminating?

Analogies can give support to arguments, by helping us to see it in terms we may be more familiar with. 1. “Just as we do not spoon-feed students so that they can develop into independent, critical thinkers, so in the same way we do not handout charity to third-world communities in a way that does not encourage their own independence”. 2. “We do not expect politicians to be honest in campaigning for re-election in the same way that we do not expect an unsupervised small child to resist the temptation to eat sweets in a sweetshop”. • What is the structure of the arguments? • What conclusion is the analogy being used to support? • Does the analogy strengthen/ weaken the main argument?

Using parallel arguments to evaluate if arguments work Someone who does not deceive his wife can nevertheless be a bad Prime Minister. So someone who does deceive his wife can be a good Prime Minister. Does this argument sound plausible? Identify the structure of it. Think of a parallel argument that would follow the same structure, and show it to be a strong/ weaker argument. Someone who is not cruel to children can nevertheless be a bad child minder. So someone who is cruel to children can be a good childminder. Here, the conclusion is clearly seen to be false. It is a bad argument – because the reason given is not good enough to establish the conclusion. You have to do more to be a good childminder, than just not be cruel to children. Therefore the PM argument is also bad: it is not enough/relevant if a PM is a faithful husband or not.

Answers to exercises 1(d) Because Xs usually have the characteristic Y, and Because Z has characteristic Y, it follows that Z is probably an X 2 (b) X did (does) not cause Y Y caused (causes) X 3 (a) In some case, the absence of X has not prevented the occurrence of Y Therefore, X does not have the disastrous results it is supposed to have.